The ClaRa library – Simulation of Clausius-Rankine cycles
ClaRa stands for the Clausius-Rankine cycle. This thermodynamic cycle process is the basis all over the world for electricity generation from the most varied energy sources – from coal-fired power plants to direct steam generation solar power plants. The Modelica library ClaRa enables the investigation of the transient behavior of such cycle processes and is available for free under Modelica License Version 2.0.
The library has been developed and validated in close cooperation with users from power plant engineering
The component models are validated against reference files and measured data
The structure of the library is laid out so that numerous questions can be processed efficiently
The library can be extended simply and comfortably
Modeling of steam boilers:
- ClaRa enables the representation of natural-and forced circulation boilers as well as Benson boilers. The heating can be provided by gas or coal dust.
- Consideration of dead times for fuel preparation and heat release as well as staged combustion air supply.
Modeling of the water-steam cycle:
- ClaRa enables the representation of extensive preheating lines and the consideration of all relevant storage containers (condensers, feedwater tanks, atmospheric storage).
- Permits the analysis of the process efficiency under transient conditions and part load.
Validation and qualification:
- The models are qualified and validated using both isolated component testers and using connected overall models. The developers work closely together with users from the industry and scientists.
- Source: University of Duisburg-Essen, Chair of Environmental Process Engineering and Plant Design, diagram accepted for publishing at the Modelica Conference 2015, Paris.
Analysis of process transients:
- ClaRa models enable the state analysis of the individual components and optimization of control under transient conditions.
- ClaRa supports the simulation of load changes (e.g. pre-qualification for primary and secondary control) and interruptions (e.g. failure of coal mills, pumps and turbines).
Design of components:
- ClaRa helps you with the design of containers (drums, storage tanks, feedwater tanks) and quick-acting stop valves under extremely dynamic operating conditions.
Development of process controls:
- ClaRa enables stability analyses and optimization of distributed control systems (DCS).
- ClaRa permits the safety-relevant evaluation of chains of steps in case of incidents.
Avoidance of critical plant states:
- ClaRa helps you to detect and avoid critical states in complex plants like cavitating pumps or evaporation in liquid pipelines.
The Dyncap and Dynstart projects
The research project was carried out as part of the COORETEC Initiative of the German Federal Ministry for Economic Affairs and Energy and had the objective of evaluating the processes necessary for the separation and storage of CO2.
The focus of the investigations was particularly on the dynamic transition behavior of future plants and the question, to what extent power plants with CCS technology can take part in the provision of control energy.
The Dynstart project is a follow up of the Dyncap project and has the goal to evaluate the Dyncap investigations under consideration of extra-low-loads, start-up and shut-down processes with its limits of operation under use of modern control strategies.
The Dyncap research project was supported by the German Federal Ministry for Economic Affairs and Energy under grant number [03ET2009A-D] from March 2011 to August 2014.
The Dynstart research project is supported by the German Federal Ministry for Economic Affairs and Energy under grant number [03ET7060E] from August 2015 to January 2019.
Institutes & Partners
TLK-Thermo GmbH, Braunschweig
The company TLK-Thermo GmbH has many years of research and development experience in the fields of energy management, vehicle air conditioning and cooling systems as well as modeling and simulation of thermal systems and the development and optimization of controls for the most varied fields of application. The areas of work include energy generation systems, building heating systems and industrial cooling systems as well as the thermal management of alternatively powered cars. TLK Thermo also offers software products for Co-Simulation and post-processing.
XRG Simulation GmbH, Hamburg
XRG Simulation GmbH conducts system simulations by numerical methods in the automotive, process and building services field, for the aerospace and shipping industry and for power plants. XRG Simulation is specialized in energy engineering and supports industry and research institutions in research, development and improvement of products and projects. In every phase of the product life cycle XRG Simulation identifies the potential for improvement in a cost effective and time saving way. Moreover, XRG Simulation provides tailored software solutions for analyzing and optimizing products.
Institute for Thermo-fluid Dynamics (TUHH), Hamburg
The Institute for Thermo-fluid Dynamics, Technical Thermodynamics, is involved with the application of the laws of thermodynamics to technical processes. The work is concentrated on the interdisciplinary modeling and simulation of dynamic systems. At the moment, the Institute is working on several research projects in the fields of aviation, cooling and air conditioning, process technology and sustainable energy.
Institute of Energy Systems (TUHH), Hamburg
In the Institute of Energy Systems, energy processes are technically investigated and optimized. Particular emphasis is placed on the modeling and simulation of realistic constraints, supplemented by trial plants for the implementation of extensive experimental investigations. Fields of research include thermodynamic investigations of different types of power plants and CCS technologies with respect to flexibility and part-load operation.
-  Johannes Brunnemann , Friedrich Gottelt, Kai Wellner, Ala Renz, André Thüring, Volker Röder, Christoph Hasenbein, Christian Schulze, Gerhard Schmitz, Jörg Eiden: „Status of ClaRaCCS: Modelling and Simulation of Coal-Fired Power Plants with CO2 capture“, 9th Modelica Conference, München, 2012 // Download (pdf)
-  Volker Roeder, Christoph Hasenbein, Alfons Kather, Kai Wellner, Gerhard Schmitz, Johannes Brunnemann, Friedrich Gottelt, Ala Renz, Christian Schulze, André Thüring: „Das Projekt DYNCAP: Untersuchung des dynamischen Verhaltens von Dampfkraftprozessen mit CO2-Abtrennung zur Bereitstellung von Regelenergie“, Proceedings of the 44th Conference on Power Plant Technology, Dresden, Oktober, 23–24, 2012
-  Alfons Kather, Volker Roeder, Christoph Hasenbein, Gerhard Schmitz, Kai Wellner, Friedrich Gottelt, Lasse Nielsen: „DYNCAP Dynamische Untersuchung von Dampfkraftprozessen mit CO2-Abtrennung zur Bereitstellung von Regelenergie“, Abschlussbericht, Technische Universität Hamburg-Harburg, TLK-Thermo GmbH, XRG Simulation GmbH, 2015 // Download
-  Friedrich Gottelt, Kai Wellner, Volker Roeder, Johannes Brunnemann, Gerhard Schmitz, Alfons Kather: „A Unified Control Scheme for Coal-Fired Power Plants with Integrated Post Combustion CO2 Capture“ Proceedings of the In 8th IFAC Conference on Power Plant Power System Control, Toulouse, Frankreich, 2012
-  Marcel Richter, Florian Möllenbruck, Andreas Starinski, Gerd Oeljeklaus, Klaus Görner: „Flexibilization of coal-fired power plants by Dynamic Simulation“ Proceedings of the 11th Modelica Conference, Paris, 2015 // Download (pdf)
-  C. Gierow, M. Hübel, J. Nocke, E. Hassel: „Mathematical Model of Soot Blowing Influences in Dynamic Power Plant Modelling“ Proceedings of the 11th Modelica Conference, Paris, 2015 // Download (pdf)
-  Friedrich Gottelt, Timm Hoppe, Lasse Nielsen: „Applying the Power Plant Library ClaRa for Control Optimisation“ Proceedings of the 12th Modelica Conference, Prag, 2017 // Download (pdf)